No. 6704E
Disassembly & Adjustment
This video deck is a VHS type video recorder. For proper operation, only the VHS type cassette must be used.
SPECIFICATIONS AND PARTS ARE SUBJECT TO CHANGE FOR IMPROVEMENT
February 1997 Image & Information Media Systems Division, Tokai
1. REMO | OVAL PROCEDURE | E1-1 |
---|---|---|
2. MAIN | N MECHANICAL COMPONENTS | |
IDEI | NTIFICATION | E1-3 |
2-1. | Top View | E1-3 |
2-2. | Bottom View | E1-3 |
3. MAIN | N MECHANICAL COMPONENTS REMOVAL | E1-4 |
3-1. | Cassette Holder and TSS (Supply | |
Sensor) Circuit Board | E1-4 | |
3-2. | Cylinder (Video Heads) | E1-5 |
3-3. | Audio/Control (A/C) Head | E1-5 |
3-4. | Full Erase (FE) Head | E1-6 |
3-5. | ESS (Supply End Sensor) Circuit Board | DI U |
00. | and Loading Motor | E1-6 |
3-6. | ERS (Take-up Sensor) Circuit Board | LI U |
0 00 | (Take-up Reel Sensor/Take-up End | |
Sensor/Cassette Holder Switch) | E1-7 | |
3-7. | Capstan Motor | E1-7 |
3-8. | Pressure Roller Assembly | E1-8 |
3-9. | Tension Arm and Tension Band | E1-8 |
3-10. | Supply Reel Disk | E1-8 |
3-11. | Take-up Reel Disk | E1-9 |
3-12. | Take-up Sub Brake | E1-9 |
3-13. | Supply Guide Roller | E1-9 |
3-14. | Take-up Guide Roller | E1-10 |
3-15. | A/C Head Base | E1-10 |
3-16. | Take-up Guide Pole | E1-10 |
3-17. | Supply Guide Roller Base, Take-up | |
Guide Roller Base, Guide Roller | ||
Rail and End LED | E1-11 | |
3-18. | Supply Sub Brake | E1-11 |
3-19. | Cylinder Base | E1-12 |
3-20. | Supply Loading Cam Gear and | |
Take-up Loading Cam Gear | E1-12 | |
3-21. | Take-up Guide Arm | E1-12 |
3-22. | Pressure Roller Control Arm | E1-13 |
3-23. | Cassette Holder Lock Slider | E1-13 |
3-24. | Reel Gear Block, Mechanism State | |
Switch and Relay Gear | E1-14 | |
3-25. | Loading Gear | E1-15 |
3-26. | Tension Pole Drive Arm | E1-15 |
3-27. | Driving Gear | E1-16 |
3-28. | Cassette Holder Lock | E1-16 |
3-29. | Cam Gear Arm | E1-17 |
3-30. | Cassette Holder Lock Drive Arm | E1-17 |
JIGS AND TAPES FOR ADJUSTMENT | E2-1 |
---|---|
1. TAPE TRANSPORT SYSTEM COMPONENTS | |
CHECK/ADJUSTMENT | E2-1 |
1-1. Reel Disk Height Adjustment | E2-1 |
1-2. Tension Pole Position/Tension | |
Adjustment | E2-2 |
1-3. Take-up Guide Poles height | |
Adjustment | E2-2 |
1-4. Supply/Take-up Guide Rollers Height | |
Adjustment | E2-3 |
1-5. A/C Head Adjustment | E2-4 |
2. ADJUSTMENT AFTER REPLACING THE | |
CYLINDER (VIDEO HEADS) | E2-5 |
3 TENSION AND TOROUT CHECKS | F2-5 |
1. | Required Maintenance | E3-1 |
---|---|---|
2. | Scheduled Maintenance | E3-1 |
3. | Check Before Starting Repairs | E3-1 |
4. | Tool Needed for Inspection and | |
Maintenance | E3-1 | |
5. | Maintenance Procedures | E3-1 |
5- | -1. Cleaning | E3-1 |
5- | -2. Lubrication | E3-2 |
5- | -3. Greasing | E3-2 |
1. | CHASSIS | (TOP VIEW) SECTION | 4-1 |
---|---|---|---|
2. | CHASSIS | (BOTTOM VIEW) SECTION | 4-2 |
CHAPTER 1
Before removing specific parts, see the table below to check the removal procedure. Remove the parts in the left column before removing the part in the right column. Remove the parts from the the top to the bottom of the left column in order. The parts not shown in the right column can be removed independently.
Example: Parts to remove in advance before removing the tension arm in item 3-9.
3-9 | ||
---|---|---|
Tension
Arm |
||
3-1 | Cassette Holder | 1 |
3-1 |
Supply Sensor
Circuit Board |
2 |
ITE
N
No |
ITEM No.
REMOVE PARTS ORDER FOR REMOVING PARTS |
3-8
Pressurė Roller Assembly |
3-9
Tension Arm |
3-9
Tension Band |
3-10
Supply Reel Disk |
3-11
Take-up Reel Disk |
3-12
Take-up Sub Brake |
3-15
A/C Head Base |
---|---|---|---|---|---|---|---|---|
3-1 | Cassette Holder | 1 | 1 | 1 | 1 | 1 | 1 | |
3-1 | Supply Sensor |
@ |
||||||
Circuit Board | (4) | Ŵ | ||||||
3-3 | A/C Head | _ | ||||||
3-9 | Tension Arm | 3 | ||||||
3-9 | Tension Band |
|
| | | |
ITEM No. | 3-17 | 3-17 | 3-17 | 3-17 | 3-18 | 3-19 | 3-20 | 3-20 | |
---|---|---|---|---|---|---|---|---|---|
REMOVE | Supply | Take-up | Guide | End | Supply | Cylinder | Supply | Take-up | |
1754 | PARIS | Guide | Guide | Roller | LED | Sub | Base | Loading | Loading |
No. | RENOVING PARTS | Roller | Roller | кан | Brake | Cam Gear | Cam gear | ||
3-1 | Cassette Holder | (I) | 0 | 0 | 0 | 0 | |||
3-1 | Supply Sensor | × | ~ | ||||||
Circuit Board | 2) | 2 | 2) | 2 | 2 | 2 | 2 | 2 | |
3-2 | Cylinder | 3 | 3 | 3 | 3 | 3 | - | 3 | |
3-3 | A/C Head | 4 | 4 |
|
|
||||
3-4 | FE Head | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 |
3-9 | Tension Arm | 6 | 6 | 6 | 6 | 6 | 6 | ē | 6 |
3-9 | Tension Band | 7 | 1 | 7 | 7 | 1 | 1 | 1 | Ō |
3-13 | Supply Guide | ||||||||
Roller | Ű | e e | 0 | ||||||
3-14 | Take-up Guide |
@ |
|||||||
Roller | 3 | 9 | 9 | 9 | (9) | ||||
3-15 | A/C Head Base | 10 | 0 | 0 | 10 | 10 | 0 | ||
3-17 | Supply Guide | [ | [ | ||||||
Roller Base | U) | U. | U) | ||||||
3-17 | Take-up Guide | | | | | 10 | 10 | ||||
Roller Base | |||||||||
3-17 | Guide Roller | _ | 13 | 12 | (10) | 13 | |||
Rail | 6 | 6 | (13) | ||||||
3-17 | End LED | 14 | 14 | 4 | |||||
3-19 | Cylinder Base | | | 15 | 15 |
I TEM
No |
ITEM No.
REMOVE PARTS ORDER FOR REMOVING PARTS |
3-21
Take-up Guide Arm |
3-22
Pressure Roller Control Arm |
3-23
Cassette Holder Lock Slider |
3-24
Reel Gear Block |
3-24
Mechanism State Switch |
3-24
Relay Gear |
3-25
Loading Gear |
3-26
Tension Pole Drive Arm |
---|---|---|---|---|---|---|---|---|---|
3-1 | Cassette Holder | 1 | 1 | 1 | |||||
3-1 | Supply Sensor | 2 | 2 | 2 | |||||
Circuit Board | - | ||||||||
3-6 | Take-up Sensor | (Î) | |||||||
Circuit Board | Û | Ū | |||||||
3-8 | Pressure Roller | (2) | |||||||
Assembly | 9 | 3 | |||||||
3-24 | Reel Gear Block | 2 | 2 |
ITEM No. | 3-27 | 3-28 | 3-29 | 3-30 | |||
---|---|---|---|---|---|---|---|
REMOVE | Driving | Cassette | Cam Gear | Cassette | |||
PARIS | Gear | Holder | Arm | Holder | |||
ITEM
No |
ORDER FOR | LOCK |
Lock
Drive Arm |
||||
3-6 | Take-up Sensor |
|
|||||
Circuit Board | (I) | Û | |||||
3-7 | Capstan Motor | 2 | 2 | ||||
3-24 | Reel Gear Block | 2 | 2 | 3 | 3 |
|
|
3-25 | Loading Gear | 3 | 4 | 4 |
|
||
3-26 | Tension Pole |
|
|||||
Drive Arm | (4) | 6 | (5) | ||||
3-27 | Driving Gear | 6 | 6 |
|
|||
3-29 | Cam Gear Arm | 1 |
|
||||
|
1. Cylinder (Video Head) 2. Guide Roller Rail X-Value Adjust Nut Take-up Guide Roller Audio/Control (A/C) Head 6. Take-up Guide Pole 7. Pressure Roller Assembly 8. Take-up Guide Arm 9. EST (Take-up End Sensor) Circuit Board 10. EL (End LED) Circuit Board 11. Take-up Reel Disk 12. Cassette holder Lock Slider 13. Reel Gear Block 14. Supply Reel Disk 14. Supply Keel Disk 15. Tension Band 16. Tension Arm 17. Supply Guide Roller 18. ESS (Supply End Sensor) Circuit Board 19. Supply Guide Post 20. Supply Guide Pole 21. Full Erase (FE) Head
Fig. 2-1
22. Cylinder Cover
Note: For the item marked *, refer to the Removal Procedure in item 1.
Fig. 3-2
Fig. 3-1
Fig. 3-3
Fig. 3-4
Fig. 3-6
3-3. Audio/Control (A/C) Head
Fig. 3-9
Fig. 3-11
Fig. 3-14
Fig. 3-16
*3-12. Take-up Sub Brake
Fig. 3-17
3-13. Supply Guide Roller
Fig. 3-19
Fia. 3-20
3-16. Take-up Guide Pole
Fig. 3-22
Fig. 3-23
1) Remove 3 screws (1). (See Fig. 3-24)
Caution when reinstalling Align mark (A) on the supply loading cam gear and mark (B) on the take-up loading cam gear when reinstalling them. Check that the supply and take-up guide roller bases are in the unloading (stop) state (as shown in Fig. 3-26).
Fig. 3-25
Fig. 3-24
Fig. 3-26
Fig. 3-27
Fig. 3-28
1) Remove 1 washer (1) and release 1 tab (2). (See Fig. 3-29)
Fig. 3-29
(BOTTOM VIEW) Fig. 3-31
1) Pull out the loading gear. (See Fig. 3-33)
Caution when reinstalling 1) Refer to the Fig. 3-32
Fig. 3-33
*3-26. Tension Pole Drive Arm
Pull out the tension pole drive arm. (See Fig. 3-34)
Caution when reinstalling 1) Refer to the Fig. 3-32
Fig. 3-34
*3-27. Driving Gear
Fig. 3-35
Fig. 3-37
Fig. 3-39
Fig. 3-40
The tape transport system is the path from the supply reel disk to the take-up reel disk via the video heads. The tape treansport components, especially the components which come into direct contact with the tape, should be kept clean without damage, dust and oil, etc. adhering to the contact surfaces. The tape transport system is adjusted before shipment from the factory, so when any transport compoents are replaced, the transport system is stabilized by correctly adjusting the new components.
Fig. 1-1
1-2. Tension Pole Position/Tension Adjustment (Fig. 1-2)
Fig. 1-2
Turn guide roller height adjustment screw a little at a time to flatten waveform.
Fig. 1-5
Perform the height, tilt and azimuth adjustments repeatedly to determine the A/C head installation position, then adjust the X-value. Detailed adjustment below is the procedure when the A/C head is replaced; be sure to do precise adjustment after rough adjustment.
Note: For the X-value adjustment, refer to the service manual (electrical adjustment) issued for each model.
Fig. 1-7
Fig. 1-6
When the cylinder is replaced, the relative height with respect to the guide rollers or the X-value, etc. drifts (this drift is smallwhen the cylinder is replaced correctly). Therefore, it is necessary to readjust the tape transport system and servo system. Perform checks and adjustments by the following steps.
It is necessary to check the tension, torque and compression strength in the tape take-up section and moving section to smoothen the tape transport and to satisfy the basic performance of the VCR. When the tape transport is not smooth or the tape speed is abnormal, detect the faulty section by this checking, and then check again after replacing the faulty parts with normal ones to complete the work.
Fig. 2-1
Fig. 3-1
ltem | VCR Operation |
Measured
Reel |
Measurement Value | Remarks |
---|---|---|---|---|
Main brake | STOP | Supply | 140 g·cm or more | Fig. 3-1 |
torque | 5101 | Take-up | 100 g·cm or more | Fig. 3-1 |
Slack removal
torque |
UNLOADING | Supply | 90∼200 g·cm | Fig. 3-1 |
Fast forward
torque |
F.FWD | Take-up | 400 g·cm or more | Fig. 3-1 |
Rewind torque | REW | Supply | 400 g·cm or more | Fig. 3-1 |
Take-up torque | PLAY | Take-up | 80~110 g·cm | Fig. 3-1 |
Back-tension
torque |
F.FWD
REW |
Supply
Take-up |
4∼10 g·cm | Fig. 3-1 |
The recording density of a VCR is much higher than that of an audio tape recorder. components must be very precise to ensure compatible with other VCRs. If any of these components are worn or dirty, the symptoms will be the same as if the part is defective. To ensure a good picture, periodic inspection and maintenance, including replacement of worn-out parts and lubrications, is necessary.
Schedules for maintenance and inspection are not fixed because they are greatly according to the way in which the customer uses the VCR, and the environment in which the VCR is used. But, in general home use, a good picture will be maintained if the inspection and maintenance is done every 1.000 hours. Table 1 shows the relation between time used per day and inspection period.
lable 1 |
---|
When insp | ection is ne | ecessary | |
---|---|---|---|
Average hours | About | About 18 | About |
used per day | l year | months | 3 years |
↓ | Ļ | Ļ | |
One hour | |||
Two hours | |||
Three hours |
The faults occurring in the playback picture as shown in Table 2 can be remedied by cleaning and oiling. Check the need for lubrication and the conditions of cleanliness in the unit. Check with the customer to find out how often the unit is used. If from that you determine that the unit is ready for inspection and maintenance, check the parts shown in Table 2.
Та | b | L | е | 2 |
Phenomenon | Inspection Location |
---|---|
Poor S/N, no | Dirt on video head |
color | or it is degraded |
Tape does not run
or tape is slack |
Dirt on pressure roller,
cylinder or in tape transport system |
Vertical jitter |
Dirt on video head
or in tape transport system |
Low volume or | Dirt on video head or |
sound distorted | it is degraded |
Color beats |
Dirt on full erase (FE)
head or it is degraded |
Name |
Oil or Greasing
Location |
|||
---|---|---|---|---|
Sonic Slidas Oil
(#1600) |
Oil low-speed rotating sections | |||
Froil
(G31-SAY) |
Lubricate metal or molded
section under light load |
|||
Molicoat (PG-641) |
Lubricate metal or
molded sections under light load |
|||
Lock paint | Fix adjustment screws and nuts. |
First use a cleaning tape. Read its instruction sheet carefully before using it. If dirt on head is too stubborn to remove by tape. use the cleaning kit. Moisten the cleaning stick with cleaning fluid at the point indicated. Touch the stick to the head tip and gently turn the head (rotating cylinder) to the right and left. (Do not move the stick vertically and make sure that only the chamois leather on the stick comes into contact with the head Otherwise, the head may be damaged.) Thoroughly dry the head. Then test run a tape. If cleaning fluid remains on the video head, the tape may be damaged when in comes into contact with the head surface
cleaning fluid
leather to the head tip and gently turn the head
Use the oiler to apply one or two drop of Sonic Slidas oil. Make sure not to use too mach oil because it may spill over or leak out coming into contact with rotating parts and causing slippage or other problems. If too much oil is applied, wipe clean with alchohol.
Lubricate the specified locations only when replacing components. Refer to the exploded views for the lubricating locations.
Apply grease Froil or Molicoat, with a stick or brush. D0 not use excess grease. It may come into contact with the tape transport or drive system. Wipe any excess and clean with gauze moistend with alcohol.
Grease the specified locations only when replacing components. Refer to the exploded views for the greasing locations.
Caution: The following table does not apply to all units. The maintenance/inspection schedules depend on how the unit is used and the environment in which it is used.
Hours | 1000 | 2000 | 2000 | 4000 | E000 | 0000 |
---|---|---|---|---|---|---|
Component | 1000 | 2000 | 3000 | 4000 | 5000 | 6000 |
Video heads (upper cylinder) | C / R | C/R | C / R | C / R | C∕R | C / R |
Audio/control head | С | C/R | С | R | С | C/R |
Full erase head | С | С | С | R | С | С |
Supply guide roller | С | С | С | С | С | С |
Supply guide pole/post | С | С | С | С | С | С |
Take-up guide roller | Ç | С | С | С | С | С |
Take-up guide pole/post | С | С | С | С | С | С |
Tension band | R | R | R | |||
Supply reel disk | С | С | С | С | С | С |
Take-up reel disk | С | С | С | С | С | С |
Impedance roller | С | С | С | С | С | С |
Pressure roller | С | R | С | R | С | R |
Reel drive belt | С | R | С | R | С | R |
Capstan shaft | C | C | 0 | |||
(capstan motor) | U/K | C | C/R | С | C/R | |
Loading motor | R | R | R | |||
Cylinder motor (lower cylinder) | R | R | R |
C : Cleaning
R : Parts replacing
.
E4 Ν
HITACHI LTD. TOKYO JAPAN International Sales Division, THE HITACHI ATAGO BLDG. No. 15 -12 Nishi-Shinbashi, 2 - Chome, Minato-Ku, Tokyo 105, Japan Tel. Tokyo 3 32581111
HITACHI SALES EUROPA GmbH Am Seestern 18, 40547 Düsseldorf, Germany Tel. 0211 5291 50
HITACHI SALES (HELLAS) S.A. 91, Falirou Street, 117-41 Athens, Greece Tel. 92 42-620-4
HITACHI HOME ELECTRONICS (EUROPE) Ltd. Hitachi House, Station Road, Hayes, Middlesex UB3 4DR, England Tel. 0181 849 2000
HITACHI SALES IBERICA, S.A. Gran Via Carlos Tercero.101,1 -1 Barcelona 08028 Tel. 3- 330.86.52
HITACHI FRANCE (RADIO-T.V.-ELECTRO-MENAGER) S.A. 4, allée des Sorbiers, Parc d'active de Chêne, 69671 BRON Cedex, France Tel. 72 14-29-70
HITACHI HOME ELECTRONICS NORDIC Domnarvsgatan 29 Lunda, Box 62 S-163 91 Spanga, Sweden Tel. 08 621 8250
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